The Doctor's
Perspective
AN
ADVOCATE FOR BETTER CARE
OCCLUSION
THEORIES
Clayton A. Chan, D.D.S.
DEFINING OCCLUSION:
The Websters dictionary defines occlusion as: the bringing of the opposing
surfaces of the teeth of the two jaws into contact, also the relation between
the surfaces when in contact.
OCCLUSION
THEORIES "Occlusion" is such a fundamental element in dentistry that
almost all departments of dentistry are concerned with it. It has been one of
the key issues for many years for every generation of our profession.
The following article is posted on this website with personal permission from Dr.
Robert R. Jankelson. It is taken from the Forward of his textbook titled
"Neuromuscular Dental Diagnosis and Treatment".
In prosthodontic dentistry where the aim is artificial reconstruction of
occlusion to harmonize with the entire stomatognathic system, two major schools
of theory have been advocated: One is the mechanical occlusion theory initiated
by Dr. Gysi, where emphasis is placed upon mandibular movement. The other is a
theory of functional occlusion system based on neuromuscular physiology.
The mechanical occlusion theory has been dominant in prosthodontics over the
past 100 years and has led to the development of numerous adjustable
articulators and related clinical techniques.
On the other hand, the oral physiology theory indicates that the functional
occlusion system is made up of three major components: teeth, muscles, and
temporomandibular joints. Occlusion is maintained by the activities of the
masticatory muscles which are controlled by neural integration of the feedback
from peripheral proprioceptors and the reflex mechanism from the central nervous
system.
Unfortunately, however, this functional occlusion system theory based on
neuromuscular physiology was overshadowed by the mechanical and geometric
occlusion theory until about 1970. This was due to lack of scientifically
supporting technology to link observations to clinical practice.
In 1970, Dr. Bernard Jankelson successfully developed electronic instrumentation
for the diagnosis and treatment of stomatognathic disorders.
Review of the mechanical occlusion theory was triggered by his concept that a
clinical approach to occlusion should not be hypothetical, but must have a firm
theoretical and experimental basis derived from the total physiological
phenomenon of the organism. The masticatory muscles, which position and connect
the mandible to the skull, should be the focal point of correct occlusion.
His physiologic approach to occlusion and techniques with scientific back-up has
brought about new dimensions not only to patients suffering from stomatognathic
pain which could not be cured by conventional occlusion theory, but also to the
dentist seeking to understnad what the true occlusion should be.
His concept has further been developed by many researchers and distinguished
clinicians, and is now recognized as an established clinical procedure with
scientific verification.
Written by:
Department of Prosthetic Dentistry
Okayama University Dental School
Okayama City, Japan
PHYSIOLOGIC OCCLUSION: The
occlusion of choice The aim and goal of physiologic occlusion is to have all the teeth fully
occluded when the jaw joints are in the unstrained, rested, physiologic
(neutral) posture. This occlusion should allow all the teeth to harmoniously
separate in all the natural chewing and sliding motions without creating harm
and interferences of one another, neither causing antagonistic muscle splinting
to stimulate myofacial pain disorders.
Dr. Chan is a strong advocate of a physiologic/ neuromuscular occlusion.
Formerly trained and practiced the gnathological concepts for years, he is vary
aware and understands both sides of the occlusion issue. He realizes that these
issues hit home to those in the academic, lecturing and teaching arena of
dentistry. He also realizes that ignoring these issues will not perpetuate
changes that are absolutely needed in the educational arena of the dental
profession. He is an advocate for reform and change in this area of dental care.
Physiologic occlusion is the most natural and highest order of teeth fitting
together in relation to unstrained TMJ's (temporomandibular joints or jaw
joints), jaw bones, muscles, ligaments and soft tissue of the mouth. In the
dental profession we have observed that nature has given us a template or a blue
print which can be followed in order that this complex anatomy can function in
harmony with one another and in a manner that prolongs the health of our teeth
while biting and chewing.